Title (fr)

Publication

Application

Priority

JP 17706599 A 19990623

JP 2000152590 A 20000524

Abstract (en)

A microcomputer (1) has a built-in memory and is accessible to an external memory. The microcomputer executes a specific area branch instruction "JM" as an executable instruction. The specific area branch instruction "JM" is a branch instruction restricted to jump to only a specific area (12) of a memory space (10) and is a single instruction having a minimum instruction length. The microcomputer (1) allocates at least one of a real arithmetic subroutine (14), an integer division subroutine (16), and a bit handling subroutine (18) to the specific area (12). A program of this microcomputer is configured to jump to the selected subroutine (14-18) allocated to the specific area (12) in response to the specific area branch instruction "JM". Accordingly, the required program size can be reduced. When the programs are stored in the external memory, it becomes possible to suppress an increase of the execution time which is required for invoking each of the subroutines (14-18). <IMAGE>